Context: To identify various causes, risk factors, age and sex distribution associated with sudden and unexpected natural deaths (SUNDs) in young adults of age between 18 and 35 years. Materials and Methods: Retrospective analysis of autopsy reports and medical records of all SUNDs that occurred instantaneously or within 24 hours of onset of symptoms in young adults, between 2001 and 2009. Result: Of the total 6453 deaths autopsied during 2001-2009, 64 (0.99%) were SUNDs in young adults, chiefly in males between 30 and 35 years of age. Non-cardiac causes significantly predominated (73.4%) over cardiac causes (7.8%). Most of the SUND cases were due to preventable causes, including infections (54.6% cases), cerebrovascular accidents (9.37%) and ischemic cardiac causes (6.25%). Sudden adult death syndrome (SADS) accounted for 18.75% deaths. Conclusion: SUND in young adults is preventable. A meticulous post-mortem examination with special attention to the conduction system of heart and detailed toxicological analysis can pinpoint the cause of death in SADS.

How to cite this article:Chaturvedi M, Satoskar M, Khare MS, Kalgutkar AD. Sudden, unexpected and natural death in young adults of age between 18 and 35 years: A clinicopathological study. Indian J Pathol Microbiol 2011;54:47-50

How to cite this URL:Chaturvedi M, Satoskar M, Khare MS, Kalgutkar AD. Sudden, unexpected and natural death in young adults of age between 18 and 35 years: A clinicopathological study. Indian J Pathol Microbiol [serial online] 2011 [cited 2015 Mar 3];54:47-50. Available from: http://www.ijpmonline.org/text.asp?2011/54/1/47/77323

Introduction

Sudden unexpected natural death (SUND) in an adult without any significant past history of prolonged illness has been a subject of continuing interest amongst medical professionals. This subject has been widely studied in western countries as compared to India. There is only one published study on this subject from India by Kasthuri et al. [1] The subject of SUND in young adults has been studied even less. Worldwide literature search showed only few studies that have analyzed various cardiac and non-cardiac causes of SUND in young adults from general population. [2],[3],[4] There is no published study of SUND in young adults from India.

The aim of the present study was to know various cardiac and non-cardiac causes, risk factors and age and sex distribution associated with SUND in young adults of age group between 18 and 35 years from general population and to compare the data with that obtained from other parts of the world.

Materials and Methods

This study was conducted in a tertiary care teaching hospital which caters to lower and middle income group population. Majority of these patients came from slum areas.

All autopsies performed in this institute are medicolegal. Autopsy is asked for whenever the cause of death is unknown or unnatural.

As there is lack of standard definition of sudden death in adults, the present study was based on the definition given by a single Indian published study on SUND in adults. [1] SUND was defined as natural death occurring instantaneously or within 24 hours of onset of symptoms, in a patient who may or may not have a known pre-existing disease, but in whom the mode and time of death is unexpected.

A retrospective analysis of SUND that occurred during a 9-year-period from 2001 to 2009 was performed. Inclusion criteria were (1) young adults of age group between 18 and 35 years, who died instantaneously or within 24 hours of the onset of symptoms; (2) patient was admitted to the hospital for the symptoms and (3) diabetics and hypertensive, stable on treatment. Exclusion criteria were (1) deaths prior to admission or after 24 hours of the onset of symptoms; (2) cases with previous coronary symptoms; (3) cases with known congenital heart disease, chronic renal failure, chronic obstructive pulmonary disease, chronic hepatic disease or malignancy; (4) pregnancy related deaths; (5) deaths due to road traffic accidents, blunt trauma, stab wounds or bullet wounds and (6) unnatural deaths (drowning, poisoning).

A complete autopsy was performed. Detailed gross examination findings of all the organs were noted. Tissue sections were taken from all organs and studied by routine hematoxylin and eosin staining. Final diagnosis was given considering the clinical history, gross and histopathology.

Results

The total nonviolent and nontraumatic deaths that were autopsied during a 9-year span of 2001-2009 in our tertiary care hospital were 6453. Of these, total SUND in young adults was 64 (0.99%). There were 49 (76.6%) males and 15 (23.4%) females, chiefly in the age group 30-35 years (34, 53.1%) [Table 1]. A numerical and percentage breakdown of the 64 cases in this series by organ system with reference to cause of death is presented in [Table 2]. It was observed that non-cardiac causes significantly predominated (73.4%) over cardiac causes (7.8%). Non-cardiac causes included central nervous system (CNS) diseases, gastrointestinal (GI) diseases including hepatic and pancreatic diseases, respiratory system (RS) diseases and febrile illnesses.

Table 1: Age and sex distribution of sudden and unexpected natural death in young adults

Of the 64 cases of SUND, only 5 revealed pathology in the heart at autopsy. All were males, previously asymptomatic, and presented with sudden chest pain. Three were in the age group 30-35 years. Two revealed healed myocardial infarct. One case had 90% stenosis of left anterior descending coronary artery, and electrocardiogram (ECG) was suggestive of old anterior wall myocardial infarction. The other case had 30-40% block of left anterior descending coronary vessel with changes of polymorphic ventricular tachycardia on ECG. Two other cases showed recent myocardial infarct with 25% block of two major coronaries due to atherosclerosis. One case showed only left ventricular hypertrophy (LVH) and grade I atherosclerosis in aorta.

Non-cardiac Causes

Amongst the non - cardiac causes, the leading causes of sudden death in young adults were diseases related to gastrointestinal tract and related organs (17, 26.6%), closely followed by febrile illnesses (14, 21.8%). CNS and respiratory diseases caused sudden death in 8 (12.5%) cases each.

Gastrointestinal and Related Organs' Diseases

Of 17 cases, there were 13 males and 4 females. Sudden death under this category was chiefly due to acute gastroenteritis (seven cases) and perforative peritonitis (five cases). Autopsy did not reveal any specific pathology in 11 cases. In one case of perforative peritonitis, autopsy revealed gastric ulcer perforation. The mode of death was hypovolemic shock following massive gastrointestinal hemorrhage or dehydration due to vomiting or diarrhea. History of alcoholism was associated with hepatic and pancreatic diseases in the form of alcoholic cirrhosis (one case), submassive hepatic necrosis (one case) and acute hemorrhagic pancreatitis (two cases) with massive gastrointestinal hemorrhage, hepatic encephalopathy and shock as mode of death, respectively. A single case of alcoholic liver disease revealed only marked steatosis at autopsy and mode of death was intrapulmonary hemorrhage.

Febrile Illness

There were 14 cases of febrile illness (13 males, 1 female), of which 4 were diagnosed as malaria and 1 as leptospirosis, with the help of laboratory investigations and autopsy findings. In majority of the cases of acute febrile illness (nine cases), laboratory investigations were negative for malaria, leptospirosis and dengue, and autopsy also could not pinpoint the etiology of fever. Intrapulmonary hemorrhage was the commonest mode of death in febrile illnesses.

CNS Diseases

Cerebrovascular accidents accounted for sudden deaths in six of eight cases. There were five males and one female. All cases were associated with history of malignant hypertension. One female died of pyogenic meningitis and one succumbed to viral meningitis.

Respiratory Diseases

All eight cases were females and sudden death was due to infective respiratory diseases.

Other Unspecified Causes (Sudden Adult Death Syndrome)

Twelve cases (eight males and four females) were included in this category as no satisfactory cause could be found from the necropsy or from a review of the medical history. Six cases (50.0%) were in the age group 30-35 years and 3 cases each (25.0%) were in the age groups of 24-29 years and 18-23 years. In five cases, the chief clinical presentation was sudden onset unconsciousness, altered sensorium or gasping and therefore no medical history could be elicited from these patients. At autopsy, there were no significant findings. One case presented with sudden chest pain and his ECG revealed tall T wave and ventricular tachycardia. There was no prior history of hypertension, diabetes mellitus or ischemic heart disease. He died within half an hour of admission in our hospital. At autopsy, heart was macroscopically and microscopically normal. Three cases each showed unexplained massive cerebral edema or adult respiratory distress syndrome. Toxicological analysis was not performed in any of the cases.

Cases were further analyzed on infective versus noninfective causes. There was slight predominance of infective causes (35, 54.6%) over noninfective causes (29, 45.3%). Febrile illnesses and gastrointestinal infections were more common in males and respiratory infections were more common in females.

Discussion

Most of the studies on this subject are from western countries. A comparison of the data of the present study with that of similar studies from west is presented in [Table 3].

Table 3: Comparison of the incidence and percentage of various causes of sudden death observed in present study with that observed in similar studies from west

It is difficult to compare the incidence of sudden death in different parts of the world because it varies largely as a function of prevalence of various diseases in different countries, environmental factors, and genetic factors. Besides this, the range observed in the reported incidence of sudden death in various studies [Table 3] is probably due to various definitions of sudden death, inclusion criteria, and age groups considered for the study.

Cardiac Causes

Among adolescents and young adults, the incidence of sudden cardiac death (SCD) is approximately 1 per 100,000 population per year. It begins to increase in adults older than 30 years to approximately 1-2 per 1000 per year. [5] In developed countries, coronary atherosclerosis is by far the most common finding in cases of SCD in patients over 30-35 years of age. Coronary atherosclerosis may result in sudden death by acute ischemia or arrhythmias secondary to healed infarct. [6] Similar observations were noted in the present study. However, overall incidence of SCD in the present study was very less as compared to other studies [Table 3]. This may be due to the difference between the age distribution of the other study groups (20-45 years and 20-39 years) and that of the present study (18-35 years) and the exclusion of cases with previous coronary symptoms. Mechanism of death in one case that revealed only LVH at autopsy could be attributed to increase in the frequency and complexity of ventricular arrhythmias. [7]

Gastrointestinal and Related Organs' Diseases

One case had history of chronic alcoholism and at autopsy revealed only marked steatosis. Sudden death in such cases has been attributed to abnormality in the conduction system of the heart, manifested as a prolonged QT interval. [8] However, in our case, ECG report was not available as the patient died within 1 hour of onset of symptoms.

Culture studies and Gram's or Ziehl Neelson's stain on tissue sections could have helped in demonstration of organisms in cases of perforative peritonitis and acute gastroenteritis. Pathologic changes may be subtle or nonspecific.

CNS Diseases

Earlier studies [2],[3] also recorded chief cause of sudden death to be cerebrovascular accidents. However, Bennani et al.[4] reported sudden deaths in cases of epilepsy and a case of meningococcal meningitis. In the present study, none of the cases had epilepsy.

Respiratory Diseases

Similar to that of previous studies, [2],[3] tuberculosis and pneumonia formed the chief causes of sudden death under this category. However, incidence was much lower in the present study [Table 3].

Infective Versus Noninfective Causes

Unlike other studies, [2],[9] there was no association of alcoholism and infection. and slight predominance of the infective causes can be attributed to poverty, illiteracy, and unhygienic and crowded environment of the population studied,

Unspecified Causes

In 32.3% cases [9 cases of acute febrile illness and 12 cases labeled as sudden adult death syndrome (SADS)], exact underlying disease could not be detected even at autopsy. Macroscopically and microscopically, hearts in cases of SADS were normal. In most of the cases due to rapidity of events important emergency investigations like ECG, chest X-ray, etc., were not available. Besides this, due to lack of reliable witness or close relatives, in many cases, detailed clinical history could not be retrieved.

Conclusion

The above observations suggest that most of the SUNDs were due to preventable causes including infections (54.6% cases), cerebrovascular accidents (9.37%), and ischemic cardiac causes (6.25%).

A meticulous post-mortem examination along with study of conduction system of heart and detailed toxicological analysis can pinpoint the cause of death. A detailed clinical protocol should be designed for physicians working in emergency services, and accessibility to necessary emergency investigations is necessary for better clinicopathological understanding of sudden deaths in young adults.